Recently, as the elevator technology is developed rapidly, more and more special elevators are used in different working conditions. In lifting application in mine shafts, a flexible guide-based mine elevators are even more widely applied, owing to their simple structure, easy installation, high safety, and high controllability, etc. In terms of safety performance of the special elevators based on flexible guide, a speed limiter and a safety clamp are usually used in combination to implement overs-peed protection. When emergency braking, the safety clamp of the elevator instantaneously seizes the flexible brake steel wire rope under the linkage functions of the speed limiter, so as to realize braking. At the moment of braking, the brake steel wire rope suffers a huge impact owing to the high inertia of the entire elevator unit. Therefore, an anti-drop buffer must be connected to the upper end of the brake steel wire rope, so as to reduce the impact on the steel wire rope, protect the steel wire rope and prolong the service life of the steel wire rope.
An existing anti-drop buffer is mainly consisted of a spring and a guide sleeve, and it provides buffer protection for the steel wire rope by means of the buffer action of the spring in the anti-drop protection process. However, in the anti-drop buffering process, the gravitational potential energy of the elevator is converted into the elastic potential energy of the spring owing to the contraction of the spring, and, at the end of the braking, the spring will release the potential energy and drives the elevator to backstroke, which severely increases the safety risk to the persons and materials transported in the elevator.